In a commercially available thermal ink-jet printer, known as PAINTJET.RTM. and available from Hewlett-Packard Company, Palo Alto, Calif., yellow, magenta, and cyan colors are provided by inks containing one of two specific dye sets. In the first dye set, yellow, magenta, and cyan colors are provided by inks containing Direct Yellow 86, Direct Red 227, and Acid Blue 9, respectively, while in the second dye set, these colors are provided by inks containing Acid Yellow 23, Acid Red 52, and Acid Blue 9.
The first dye set yields poor color, chroma, and trueness in concentration ranges suitable for the thermal ink-jet pen when jetted onto overhead transparencies. The second dye set yields excellent hues and chromas, but evidences red fading to the magenta in very short time periods upon exposure to light.
It is desirable to provide a dye set that can be used with overhead transparencies and with the special coated paper used in the PAINTJET.RTM. printer to provide vivid, true colors that do not fade upon exposure to light.